Study Finds Hispanics Diagnosed with Blood Cancers at Younger Age

Hispanics are diagnosed at a significantly younger age than non-Hispanic white individuals in chronic and acute leukemias (both myeloid and lymphoid), myelodysplastic syndrome (MDS), and myeloproliferative neoplasms (MPNs), according to a study presented during a press briefing at the American Association for Cancer Research (AACR) Virtual Annual Meeting II, held online June 22-24, 2020.¹

Even further, Hispanics with acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML) or chronic myeloid leukemia (CML) who were diagnosed near the US/Mexico border experienced worse overall survival (OS) compared with Hispanics diagnosed in other areas of Texas. Investigators suggested that, given the overall findings, there appears to be evidence that disparities in outcome by ethnicity may be different in El Paso compared with the rest of Texas.

“[The] Hispanic population represents the largest and fastest growing minority group in the United States, representing 18% of the entire population,” Alfonso Bencomo-Alvarez, PhD, a postdoctoral research associate in the laboratory of Anna Eiring, PhD, at Texas Tech University Health Sciences Center El Paso, said in a presentation of the data. “[Cancer represents] the second cause of death in the United States and the first cause of death among the Hispanic American population.”

Using the Texas Cancer Registry for hematologic malignancies diagnosed in the state of Texas between 1995 and 2016, researchers retrospectively analyzed patients with ALL (n = 3,228), AML (n = 12,807), acute promyelocytic leukemia (APL; n = 1,002), chronic lymphocytic leukemia (CLL; n = 18,296), CML (n = 5,659), MDS (n = 10,875), and MPNs (n = 1711). In total, 53,578 patients were identified as evaluable for the study, including 42,756 non-Hispanic white individuals and 10,822 Hispanic. Data from other races were excluded due to low incidence in the analyzed regions.

“In contrast to the Hispanic population across the US, which is heterogeneous and includes Hispanics from various countries, the majority of Hispanics in Texas and at the border are Mexican,” Bencomo-Alvarez said in a press release.² “Therefore, studying Hispanics in this region gives us the opportunity to study a largely Mexican population as a way to better understand the disparities in this group.”

Overall, researchers found that Hispanic patients were diagnosed at a significantly younger age in all diseases analyzed (P < .0001), with those of Hispanic ethnicity having a higher risk ≤40 years and those of non-Hispanic ethnicity having a higher risk >40 years. The worse prognosis identified for Hispanic individuals also correlated with a lower socioeconomic status and an increase in comorbidities.

“In general, Hispanics had more comorbidities, a general lack of health insurance, and worse socioeconomic status compared with non-Hispanics,” Bencomo-Alvarez explained.

Notably, in unadjusted analyses, Hispanics diagnosed with myeloid malignancies had significantly better OS than non-Hispanic white patients (P < 0.0001), though no significant differences were observed for patients with other types of leukemia. Following age adjustment, a clear disparity was discovered in the 10-year survival rate for Hispanics age 18 to 49 versus their non-Hispanic white counterparts (ALL: 28% vs. 39% [P < 0.0001]; APL: 69% vs 76% [P = 0.03]); no significant differences were observed in other diseases.

Investigators also compared the 10-year survival rates of 1,160 Hispanic patients diagnosed in El Paso versus that of 9622 Hispanic patients diagnosed throughout the rest of Texas. Ultimately, they found that the 10-year survival rates for Hispanic patients with ALL, AML, or CML were significantly lower for those who lived in El Paso than for those who lived elsewhere in Texas (ALL: 28 percent vs. 31 percent [P = 0.0164]; AML: 13 percent vs. 22 percent [P < 0.0001]; CML: 43 percent vs. 57 percent [P = 0.016]).

However, a limitation of the study was that incidence and survival data about Hispanics living at the border was limited to those living in El Paso and surrounding areas. In addition, some subgroups were limited by a smaller sample size.

Moving forward, the researchers aim to identify potential biological factors that may increase the risk of blood cancers in Hispanics and possible ways to address this disparity.

References:

1. Survival May Be Lower for Hispanic Patients with Blood Cancers Who Live Near the United States/Mexico Border [news release]. Philadelphia. Published June 22, 2020. Accessed June 22, 2020.

2. Bencomo AE, Rubio AJ, Gonzalez MA, et al. Retrospective study of incidence and survival for patients with hematological malignancies residing at the U.S./Mexico border. Presented at: AACR Virtual Annual Meeting II, held online June 22-24, 2020.